Re: GLR: modification of $1

[Frank Heckenbach]

Paul Eggert wrote:

> Frank Heckenbach <address@hidden> writes:
> 
> > I'm just referring to what yyfill does (especially when called
> > multiple times for multiple uses of $1). I don't know exactly what
> > GCC can optimize away,
> 
> I see little chance that a C compiler could be smart enough to
> optimize $1 in the existing GLR parser as much as it can optimize $1
> in the existing LALR parser, even assuming GLR's yyfill is inlined.
> Suggestions for improvement are welcome, but I expect they won't be
> trivial.

One idea would be that bison determines the smallest n for which $n
is used within each action (if any), and calls YYFILL(n) once at the
start of the action -- if I understand correctly what yyfill does.

Frank

-- 
Frank Heckenbach, address@hidden
http://fjf.gnu.de/
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